Hi, 

We can't tell for sure from the photos but thank you for sending them. It looks like it is a type of psocid (pronounced so-sid). Commons psocids that are outside are called Barklice and they are harmless to plants. 

Our page with information is on Booklice, another type of psocid. 

The leaves and die back on the rhododendron could be a few different factors. You can review our Rhododendron diagnostic page to learn about different common problems. 

The leaf spots and browning look pretty typical for rhodies coming out of the winter and usually new growth covers the old damaged leaves and they will eventually fall. 

The branch dieback could be a sign of botryosphaerie which is a fungal disease. Fungicides are not curative of this and we don't recommend using them. You can prune off the dead branches and make sure that any needed watering is regular during times of drought. 

Let us know if you have further questions. 

Emily